Structural evolution of cobalt oxide–tungsten oxide nanowire heterostructures for photocatalysis

Li, Yuan; Chopra, Nitin

doi:10.1016/j.jcat.2015.06.015

Cited by 32 publications

(13 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From above comments, one can understand that the existence of stress also takes a critical role in the growth of metal oxide nanowire in such thermal oxidation process [27,37,38]. Thus, creation of extra surface stress before the growth would be another promising approach to increase the spatial density of grown nanowires.…”

Section: Influence Of Substrate Treatment and Additivesmentioning

confidence: 98%

“…Another surface-treating method is regarded as work hardening. For instance, S. Jin et al [27] found that the work hardening of the steel substrate by shot-peening significantly improved the growth of Fe 2 O 3 nanowires. In this study, we treated the Co foil with a sand blaster for various durations however no positive improvement of the growth was observed on these samples (see Fig.…”

Section: Influence Of Substrate Treatment and Additivesmentioning

confidence: 99%

“…In addition, the lattice spacing of 0.23 nm indicates their growth direction is also (311). It is worth mentioning here that such (311)-induced crystal plane of Co 3 O 4 nanostructures has been widely proposed before for favorable charge transfer in many electrocatalytic, photovoltaic and electronic devices [27,45,46].…”

Section: Variation Of Growth Parameters For Process Improvementmentioning

confidence: 99%

“…Several studies have reported the direct oxidation of a cobalt foil [24][25][26], however, the obtained Co 3 O 4 nanowires were either distributed in the edge area only [24] or have very low yield on the main surface [26]. Recently, a water vapor-assisted thermal oxidation approach was widely proposed for the growth of similar metal oxide nanowires [27][28][29]. It is believed that the presence of water vapor accelerated the thermal oxidation by promoting nucleation and nanostructure growth.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Structural and morphological evolution of free-standing Co3O4 nanowires via water vapor-assisted thermal oxidation of Co foil

Keith

Chopra

2017

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

Nanostructured cobalt oxide (Co 3 O 4) has been regarded to be of great interest for catalysis, gas sensors, and energy conversion/storage. In this paper, we reported a water vapor-assisted thermal oxidation approach for the scalable synthesis of free-standing Co 3 O 4 nanowires with controlled size, crystallization, and spatial density. Thermodynamic calculation was carried out to understand the fundamental mechanism of the water vapor-assisted nanowire formation process. For the first time, we found the incorporation of water vapor in the growth system modified the nanowires formation pathway. Cobalt hydroxide (Co(OH) 2) was recognized to take a critical intermediate role during the growth. The proposed mechanism was further verified by understanding the influence of various growth parameters on the thermal oxidation process and product morphology. It was observed that the feeding rate of water vapor and type of oxygen source have a critical influence on the spatial density of Co 3 O 4 nanowires while the temperature shows a dominant effect on the product morphology. Finally, the representative Co 3 O 4 products were characterized for their composition, optical and magnetic properties. This study accumulates deeper understanding on the fundamentals of water vapor-assisted thermal growth of metal oxide nanostructures and successfully provides a facile approach for the scale production of Co 3 O 4 nanowires for future applications.

show abstract

Section: Influence Of Substrate Treatment and Additivesmentioning

confidence: 98%

Section: Influence Of Substrate Treatment and Additivesmentioning

confidence: 99%

Section: Variation Of Growth Parameters For Process Improvementmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Structural and morphological evolution of free-standing Co3O4 nanowires via water vapor-assisted thermal oxidation of Co foil

Keith

Chopra

2017

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

show abstract

“…[6] However, their exorbitant price and lessthan-ideal durability in alkaline solution severely limited the wholesale application in the alkaline metal-air batteries. Therefore, developing novel nonprecious catalysts with highly-efficient ORR performance attracts great research attentions.Metals, metal oxides and their composites, [7,8] metal-free carbon materials, [9] and metal-N-C family [10,11] are widely studied nonprecious catalysts for ORR. The metal-free carbon materials have drawn particular interests due to their widespread pourability and excellent durability in alkaline solution, [12,13] yet the best performance is still limited by the insufficient active sites in the original pure products.…”

mentioning

confidence: 99%

Superior Oxygen Reduction Reaction on Phosphorus‐Doped Carbon Dot/Graphene Aerogel for All‐Solid‐State Flexible Al–Air Batteries

Wang

Fang

et al. 2019

Advanced Energy Materials

Self Cite

118

View full text Add to dashboard Cite

Flexible energy storage devices are highly desirable in modern portable and wearable electronics. [1,2] All-solid-state flexible batteries are of particular interest for their highly compatible assembly with the existing electronic devices. [3,4] The flexible metal-air batteries, for instance, exhibiting a theoretical energy density of 8100 Wh kg −1 , have been considered as a promising clean energy conversion source to satisfy the demand of future energy storage systems. [5] As a typical requirement of metal-air batteries, the cathodic electrode undertakes the mission of oxygen reduction reaction (ORR) and significantly determines their final discharge performance. To date, the noble metal-based electrocatalysts have been widely used as the cathodic material due to their low activation energy for ORR. [6] However, their exorbitant price and lessthan-ideal durability in alkaline solution severely limited the wholesale application in the alkaline metal-air batteries. Therefore, developing novel nonprecious catalysts with highly-efficient ORR performance attracts great research attentions.Metals, metal oxides and their composites, [7,8] metal-free carbon materials, [9] and metal-N-C family [10,11] are widely studied nonprecious catalysts for ORR. The metal-free carbon materials have drawn particular interests due to their widespread pourability and excellent durability in alkaline solution, [12,13] yet the best performance is still limited by the insufficient active sites in the original pure products. Heteroatom doping of carbon materials is a unique approach to enhance the ORR activity since it can form abundant active sites. [14,15] With this regard, phosphorus (P) exhibits more negative electronegativity and stronger electron-donating ability compared to carbon, and thus the P-doped carbon materials are considered as highly potential catalysts for aqueous metal-air batteries. [16,17] Nevertheless, currently such P-doped carbon materials still exhibit a relatively poor ORR activity compared to the commercial Pt/C catalysts, ascribing to their unsatisfied structural geometry and relatively low doping level.Recently, N, S-doped carbon dots (P-CD), where mono-heteroatoms are doped into the highly stable sp 2 -hybridized graphite structure to form the covalent bonds, have been developed as a potential carbon architecture for ORR. [18] A common problem Carbon dots have been recognized as one of the most promising candidates for the oxygen reduction reaction (ORR) in alkaline media. However, the desired ORR performance in metal-air batteries is often limited by the moderate electrocatalytic activity and the lack of a method to realize good dispersion. To address these issues, herein a biomass-deriving method is reported to achieve the in situ phosphorus doping (P-doping) of carbon dots and their simultaneous decoration onto graphene matrix. The resultant product, namely P-doped carbon dot/graphene (P-CD/G) nanocomposites, can reach an ultrahigh P-doping level for carbon nanomaterials. The P-CD/G nanocomposites are fou...

show abstract

Cobalt Tungsten Oxide Thin Films Prepared by RF‐Sputter for Photosensor

Lan

Hong

Chang

et al. 2017

Adv Materials Inter

View full text Add to dashboard Cite

This study reports the synthesis and characterization of nonstoichiometric nanocrystalline Co2.59W0.41O4 thin film by the radio frequency (RF)‐sputter technique suitable for photosensor applications. The photoconductive characteristics of Co2.59W0.41O4 thin film are investigated by fabricating a sandwich‐structure device of p+Si/Co2.59W0.41O4 thin film/indium tin oxide with Schottky barriers. The device characteristics including responsivity, light intensity response, and time response are studied. It is found that Co2.59W0.41O4 thin film exhibits good absorption (absorption coefficient ≈104 cm−1 in visible light spectrum), relatively high responsivity (Rres = 5.427 A W−1), and fast photoresponse time including rise time (tr) = 81.04 ms and fall time (tf) = 80.67 ms. Hence, the Co2.59W0.41O4 thin film is favorable for potential photosensor applications.

show abstract

Structural evolution of cobalt oxide–tungsten oxide nanowire heterostructures for photocatalysis

Cited by 32 publications

References 57 publications

Structural and morphological evolution of free-standing Co3O4 nanowires via water vapor-assisted thermal oxidation of Co foil

Structural and morphological evolution of free-standing Co3O4 nanowires via water vapor-assisted thermal oxidation of Co foil

Superior Oxygen Reduction Reaction on Phosphorus‐Doped Carbon Dot/Graphene Aerogel for All‐Solid‐State Flexible Al–Air Batteries

Cobalt Tungsten Oxide Thin Films Prepared by RF‐Sputter for Photosensor

Contact Info

Product

Resources

About